For some time now, I've been trying to understand the government's thought process as it devised the bedroom tax. I can imagine Lord Freud, its inventor, might not know enough about the social housing stock to realise it is an impractical policy (though if he doesn't even know the basics of social housing, I'm not sure why the government is letting him tinker with it); I can understand the mean-spirited attitude that resents giving poor people anything other than as little as possible (though I don't share it); I can even accept that – as bizarre as it sounds to me – the government might sincerely see the bedroom tax as a practical solution to the social housing shortage.

But what I don't understand is the rationale of a group of individuals who decide to tax people for their spare rooms, and actively include foster parents in that – or people with disabilities, or people whose children are serving overseas. I mean, there must have been a conversation at some point where one policymaker asked "what about people who need a spare room to store medical equipment to keep them alive? Are they going to be exempted?" and another replied "no, let's take money from them as well". And if that conversation didn't happen, what does that say about the level of scrutiny that goes into making government policy?

I ponder this because to me it is evidence that this government is either careless or actively cruel. There are simply no other explanations. The bedroom tax has certainly not come from a place of reason. If it had, the government wouldn't have partially U-turned by exempting foster families as it has now done, or it would have listened to all the local authorities saying they don't have the right housing stock, or it would have been deterred by warnings that the policy will lead to evictions and homelessness. That's how a reasonable government would behave, and this government is not reasonable.

We've been here before, where the government attempts to introduce a tax that is unworkable, unfair and unreasonable. The fledgling campaigns against the bedroom tax have already begun to make comparisons with the poll tax, suggesting that campaigners are aware that direct action is the only conceivable response. The poll tax was defeated with mass non-payment and protest on the streets, not with rational arguments or pleas for compassion. I get the impression that campaigners against the bedroom tax will be responding with similar inflexibility to the government. Inflexibility is something this government seems to understand.

UK Uncut's forthcoming day of action on 13 April is the obvious starting point for a sustained campaign of direct action against the bedroom tax. And what the government needs to grasp pretty quickly is that opposition to the bedroom tax will not come from hubristic activists, but from people who feel they have no choice but to fight because they are already being dragged down by a whole other set of austerity measures. For a lot of people in this country, a campaign against the bedroom tax will not be an opportunity to score political points; it will be the raft that stops them from drowning.

Over the coming weeks and months, a cocktail of local authority cuts, benefit caps, and the bedroom tax will push people into fighting back. The media and political class may condemn their actions, even if they are non-violent. There won't be any headlines depicting these protests as what they simply are: a justifiable reaction to an intolerable policy. But when the government pushes people to their absolute limit, something has to give. This year, that will happen. And if you want to know who to blame, look to Westminster.